President Donald Trump claimed to be an ally to the working class, deriding the so-called swamp and corporate control of politicians during the campaign. But the billionaire real estate developer has governed as an ally to his fellow well-connected business tycoons – cutting corporate taxes, gutting Obamacare, and abandoning the Paris Accord.

To this end, Senator Sheldon Whitehouse and a six other Democratic senators are demanding Trump and his cabinet members turn over the communications they’ve had with the Koch brothers, the billionaire brothers who agitate for big business through a well-financed, diffuse network of non-profits and political action committees.

“The close ties between individuals serving in your administration and the Koch brothers’ network have been widely reported over the last year and a half,” says the letter. “Long-standing members of the Koch network fill the ranks of the federal government, raising concerns about the network’s access to and influence over federal decision-making. Americans have a right to know if special interests are unduly influencing public policy decisions that have profound implications for public health, the environment, and the economy.”

The other senators to sign on to the letters are: Elizabeth Warren and Ed Markey, Massachusetts; Ron Wyden, Oregon; Catherine Cortez Masto, Nevada; and Tom Udall, New Mexico.

The letters, according to a news release from Whitehouse’s office, “begin a broader effort to reveal the extent of the Koch brothers’ influence within the administration. Next week, Whitehouse will lead a group of Senators in speeches on the Senate floor detailing the web of Koch-funded front groups advocating for business-friendly policies, sowing doubt in the public debate on important issues, and planting operatives within the halls of government.”

The Koch network has bragged to its donors about access to and influence over the Trump Administration. “Documents obtained by The Intercept and Documented show that the network of wealthy donors led by billionaire industrialists Charles and David Koch have taken credit for a laundry list of policy achievements extracted from the Trump administration and their allies in Congress,” according to a February post from The Intercept included with the press release.

The Koch network was initially skeptical of Trump but has since decided to extract whatever wins it can from the embattled president, who once promised to refute brothers Charles and David Koch.

“Though the Koch brothers and their donors certainly would have preferred another Republican president, the lack of policy expertise in Trump circles presented an opportunity,” according to a Public Citizen report included with the news release that says there are 44 members of the Trump team with close ties to the Koch network, including Don McGahn, the president’s lawyer, Kellyanne Conway, an advisor to Trump, Education Secretary Betsy DeVos, and Vice President Mike Pence.